The manufacture of glass fibre reinforced truck bodies is described in prior U.S. application Ser. No. 06/512,184 filed July 11, 1983 and assigned to the assignee of the present application.
The present invention relates to improvements in the apparatus described in the above application.
In the prior application, the guidance system which is used for guiding the movement of the work head about the U-shaped path includes a rack which extends around the U-shaped guide path and a pinion which is mounted on the turntable and travels along the rack. While this mechanism operates effectively to guide the work head in the required path, it has been found that this mechanism is subject to a substantial degree of wear.
This difficulty has been overcome by the mechanism of the present invention by employing a drive chain which is mounted on sprockets to follow the required U-shaped path and providing a reversible motor which drivingly engages the chain so as to move the chain in opposite directions as required to effect reversal of the direction of rotation of the turntable on which the workhead is mounted.
It has been found that the overall efficiency of the body manufacturing system can be greatly increased if a plurality of molds are provided in the molding station and the glass fibre applicator is moveable from one mold to the other to form glass fibre shells in each mold as required.
I have found that by providing a plurality of molds it is possible to ensure that the glass fibre applicator is utilized to its maximum extent while permitting a sufficient dwell time for each molded shell in each mold to permit it to be cured and to be fitted with an appropriate liner and to be removed from its mold.
To further increase efficiency, a trimming station is provided remote from each molding station and a conveyor system is provided for conveying the reinforced molded shells from each mold to the trimming station by providing the trimming station remote from the molds, it is possible to avoid contamination of the molds by the trimmings which are removed and to ensure maximum utilization of the molds for their primary purpose which is the forming of the shells and the fitting of the liners to the shells.
A further difficulty which has been experienced in attempting to provide a glass fibre applicator which can be transported from one mold to another is that it is necessary to provide power supply cables for supplying electrical and other power lines to the applicator. Difficulty has been experienced in attempting to avoid a situation where the power lines become fouled as a result of movement of the carriage on which the glass fibre applicator is mounted as the carriage moves from one mold to the other.
These difficulties have been overcome by providing a takeup means which will deploy and take up the power supply cable as the trolley moves toward and away from one end of the track on which it is mounted for movement between molds.
In processes for forming glass fibre reinforced plastic bodies where glass fibres are chopped, and sprayed together with a resin onto a mold, considerable difficulty has been experienced in attempting to provide a safe working environment for machine operators. It is necessary to extract the noxious fumes and glass fibre particles from the work station and difficulty has been experienced in attempting to achieve this objective in large open work areas such as the large molds required in the formation of truck bodies and the like.
In an attempt to provide an improved working environment there is provided a canopy for each mold. The canopies extend over and close the open top of its associated mold. An air extraction outlet is provided in the canopy at the closed end of the mold remote from the open end of the mold and an air extraction device communicates with the air extraction outlet of each canopy. In addition, a fresh air supply is provided which has outlets disposed opposite the open front end of each mold for directing a stream of fresh air into the front end of each mold to replace the contaminated air which is withdrawn by the extraction means in use.
In previous body manufacturing systems in which large glass fibre reinforced plastic bodies have been manufactured, it has been the practice to form the shell in a mold and and then manually insert reinforcing members.
It has been found that the efficiency of operation in the manufacture of glass fibre reinforced plastic bodies can be substantially increased if, following the forming of the shell in the mold, a liner is fitted to the shell with the aid of a liner inserter and after the liner has been secured to the shell, the assembly is then removed from the mold.
Because the liner must fit closely within the glass fibre reinforced plastic shell, difficulty was experienced in attempting to locate the liner in the shell when it is in the mold because the walls of the mold are substantially rigid.
To facilitate the location of the liner in the mold, there is provided a liner inserter which will support the side and end wall panels of the liner in a toed-in configuration which will facilitate the entry of the liner panels into the mold. In addition, the inserter will support the normally convex roof beams in a concave configuration prior to insertion into the mold. A jacking mechanism is provided for jacking the side and end panels of the liner into intimate contact with the walls of the shell and a release mechanism is provided for releasing the roof beams from their convex curvature so that they will extend into intimate contact with the bottom wall of the shell.
Considerable difficulty has been experienced in attempting to remove a glass fibre reinforced plastic body from a mold in which it is formed.
It has been found that a glass fibre reinforced plastic body with liners attached thereto can be removed from a mold by providing a stripper for stripping the body from the mold. The stripper includes clamps which can be clamped to opposite upper edge portions of the side panels of the liner and a suspension system which will transmit an inwardly and upwardly force to each clamp tending to draw the side walls of the molded body inwardly and upwardly to separate from the walls of the mold.
Glass fibre reinforced plastic bodies are usually made so as to be oversized when molded and it is necessary to trim the molded shells to the required configuration after molding.
In order to facilitate and expedite this trimming process, there is provided a trimming station in which trimming aids are located which include guides which can be secured to the shell which is to be trimmed so as to provide a trimming guide to facilitate the removal of access material. In addition, the trimming station provides a convenient location for installation of the floor of the body. Because the glass fibre body is in an upside-down configuration when it is molded and is maintained in this upside-down configuration when located in the trimming station, the floor can be mounted on the body when in the upside-down configuration merely by lowering the floor assembly into the open upper end of the molded body.
Because the method of manufacturing and assembling the body calls for the body to be maintained in an upside-down configuration until the floor has been fitted, it is necessary to turn the body right-side-up before it is fitted to a chassis. The bodies which are formed by the method of the present invention are generally rather large and may measure 28 feet by 8 feet by 8 feet or more and as a consequence, it is difficult to turn the bodies right-side-up without damage to the bodies and without providing a complex and expensive inverting mechanism.
To overcome these difficulties, there is provided a body inverting mechanism which will initially engage the body at a point below its centre of gravity, relocate the body clear of its surroundings, release the body to permit controlled rotation of the body under its own weight to a position in which it is right-side-up.